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Topic Review (Newest First)

06-19-2013 09:05 AM

eighty2Bbody

The 80's caprice's are a very nice ride, that's why I like them so much. Having a sbc from the factory makes them very easy to modify and can be just as fast as any other sbc car from the 60's or 70's in my opinion. All my friends give me crap about my caprice because it is extremely out of style but I don't need a shiny new car. I just can't justify paying upwards of 20 grand for vehicle and no new cars last anyway. When my buddies are poking fun at my car I just tell them yeah that car is 31 years old, 100% stock, it's completely reliable, and cost me equal to about two of your car payments.
I will throw the 327 in the 80, mostly just so I can experience a car with a 327. I am a huge sbc fan so its more of a way for myself to appreciate a part of Chevrolet history. Install the engine, get it running, drive it for a bit, that's enough for me, ill get my fix.

06-18-2013 11:49 PM

Super70DeadSled

Quote:

Could it be your mother had a '68 Impala with a 307? 1968 was the first year the 307s were available.

I really wouldn't doubt it. As a kid (16-17 years old) I fell in love with the '69 Z28. I kept debating with her about the fact that they wouldn't have put that motor in the Impala. Her friend called me on it, and he explained everything about the 302 to me. Bore, stroke, compression ratio, cam specs. I only knew it was a high revving motor, and good for road racing. At which time he told me that her '68 DEFINITELY had the 302. He obviously knew a lot more than me, so I went with it. She had the '68 and before that a '63 SS.
If she was still alive, I could ask her. She actually left the car with my Father when she left him. My family always told me that he wanted that car because it had the 302.

But I've come to find out that a lot of things I was told weren't always the truth!

Oh, and if you're gonna change the gears anyway, then sure, put the 327 in there. But for the cost of having to refresh it, I personally would sell it, and build the 350, as well as change the gears.
You don't need to race to have a fun car. My '70 hearse weighs in around 7k. It's got the 472 in it. 525 foot pounds at my foot! It's a fun car to drive. My '88 Firebird Formula has a well built 383 and a lot of suspension work. My '73 Nova has a mildly built 350, and everything else is stock. PEG-LEGGIN'!!!! My '88 CRX has a 1.6l ZC motor in it. With the intake, header and muffler, I'm probably somewhere around 120hp to the fly wheel! Sure, it's not the fastest car, but it gets me through traffic. But when I want to take it up to the mountains, it holds it's own. All of my cars are fun cars, but I've only raced two of them.

I remember working on cop cars at my last job. The box Caprices (like yours) were really nice cars. You can drive all day long and still feel comfortable. And the 350 TBI had just enough power to have LOADS of fun! It wasn't neck breaking torque, or have 0-60 times in the 4, 5 or even 6 second range, but they were fun cars! The thing about them is they had a good amount of torque at low RPMs, which makes for a fun car.

The solid lifter, Holley 4 barrel, 4speed equipped 302 engine was only available in the 67-69 Camaros with the Z28 option. Could it be your mother had a '68 Impala with a 307? 1968 was the first year the 307s were available.

06-17-2013 08:57 PM

Valkyrie5.7

It's always the same old rhetoric about levers and piston speed and this and that. We're not talking about formula one or top fuel dragsters. I've driven 1960's era C40's and C50's (big trucks with dump beds that haul big loads) those are much more massive than any Impala. What were those powered with? Oh that's right, these "supposedly only good for high-revving" 283's and 327's. We can argue the science of it at it's extreme limits all day long but all that matters is that in a PRACTICAL APPLICATION, the sum of the parts out weigh the bore to stroke ratio. ESPECIALLY on identical platforms. Small ports, small valves, the right cam and CORRECT GEARING, will make more a difference than the miniscule amount of stroke the 305 provides over the 327. The fact that the 327 can take advantage of a larger cam at a low rpm (because it's a bigger engine than the 305) is a bigger factor than the bore to stroke ratio.

06-17-2013 01:28 PM

ap72

If you're going to be cruising at super low rpm then I would get a HV oil pump and be very careful when tuning your ignition curve and idle, transition, and primary circuits on your carb.

06-17-2013 01:04 PM

eighty2Bbody

Quote:

Originally Posted by Super70DeadSled

Sorry if I'm out of line here, but first any 327 would be better than any 305 any day. Even the '90 or so TPI from the third gen Camaros and Firebirds that made something like 220hp. More cubes, more power. Plain and simple. But if we are talking about application, then the story changes entirely. He's replacing a V6. So to start out, first, he'll get more power anyway. But the 327 won't like those gears AT ALL!!!! It may have a 2004r, or even better, a 700r4 which means better first gear to get off the line, but the 327 just won't be happy in that car. Especially in OD at 75 around what, 1700 or so RPMs? But again, it will be more powerful than the 6 cylinder that blew.

As for comparing cubes to strokes, well, all things being equal, in a balanced set up, the longer stroke always makes more torque at a lower RPM. That's why the 327 was used in Rally racing. They wanted to use it in road racing, (Trans Am) but the 5 liter limit caused GM to build the 302. (as I have read) Both 327 and 302 are high revving motors. But they did offer both of them in very large (by today's standards) cars like the Impala that this 327 came from. My mother had a '67 Impala that had a 302.
Not to downgrade here, but in the Honda "Tuner" world, rod/stroke ratio is a huge concern. I won't bore you with specifics, but with a tiny motor, every little thing comes into play.
About the Caddy 500 having loads of torque, (550 in 1970 to be exact), well, we are talking about a 500 cubic inch motor! That's a LOT of displacement! But the 472 makes 525 foot pounds. The difference is just under a quarter of an inch of stroke. At that size, 25 foot pounds is nothing.

As for every 327 and 350 coming from a Vette, mine did too. I was a bigger four door station wagon version of a Vette!!!!

Sorry to sound like a broken record, but to have a more fun car, sell the 327 and use that money to build that 350 block. Being a roller cam, that is good enough reason for me. More torque with the 350, more horsepower in a usable range, so on and so on.... Anyways, the police package gave the Caprice a 350 with TBI and that was a great set up!

And about that 7.5" rear, if it has better gears, use that. You could always go to the scrap yard and get another posi unit for it, if you get tired of peg-leggin'! And like the rest of us, you like to hold on to things, so just hold on to the current rear with posi for later. If you have enough left over from selling the 327, get some gears for it!

Not trying to argue with anyone but it seems that a lot of people say that the 327 won't like my car because its a heavy big car and the 327 would like something a bit lighter. My car weights about 3900lbs with no passengers or cargo. The 327 came out of a 68 impala, that has to be about the same weight maybe more. Yes the impala came with a 4 speed and probably some decent rear end gears but that is why I planned to put in some 3.73 in my car. Originally the 80 had a 200c tranny but I swapped it out for a 200-4r for highway travel which didn't really help because my combo of small motor 2.41 gears and overdrive was just to low rpm at 70mph. It did help top speed but that's not what I was after, basically I found myself constantly manually shifting from 3 to 4. After it was all said and done I did about double my fuel mileage to work and back everyday but I had to look ahead about a mile and pre plan all my up and down hill travels accordingly. Any how back to my point I am under the impression that the 327 will be ok in the 80. I won't be racing it just driving it every day, I'm not into tearing up the streets it's way to easy to get in trouble these days and not to mention it's unsafe. I could also use the 327 to mock up the build processes for the 350 and make the 327 easier to sell if it's in a car and someone can hear it run.

06-17-2013 06:46 AM

ap72

Quote:

Originally Posted by vinniekq2

The 327 will make more power than the 305,yes. The 327 can rev higher,more freely,w/e terminology you wish to put here,,,,have a lower piston speed at same RPM,,,there fore the 327 can rev a little higher,if you take advantage of this then the power will come on later than the 305(leave the 350 out for now)

If you change the heads, cam, intake, exhaust, etc. to raise the rpm on the 327 so that the piston speed matches that of the 305 then yes that is true.

BUT piston speed is almost never a limiting factor on a street engine and we're not discussing two completely different engines, but rather two identical engines with the exception of the piston diameter and crankshaft throw.

The 327 will have more power at every engine speed when compared to an equally built 305.

06-17-2013 01:58 AM

vinniekq2

Super70DeadSled
I think that GM only offered the 302s in Camaros from 67-69.Im not aware of any other car that had that engine option? The option code started with Z28,The SS car was a Z27 and the RS was a Z22 from what I remember

06-17-2013 12:11 AM

Super70DeadSled

Sorry if I'm out of line here, but first any 327 would be better than any 305 any day. Even the '90 or so TPI from the third gen Camaros and Firebirds that made something like 220hp. More cubes, more power. Plain and simple. But if we are talking about application, then the story changes entirely. He's replacing a V6. So to start out, first, he'll get more power anyway. But the 327 won't like those gears AT ALL!!!! It may have a 2004r, or even better, a 700r4 which means better first gear to get off the line, but the 327 just won't be happy in that car. Especially in OD at 75 around what, 1700 or so RPMs? But again, it will be more powerful than the 6 cylinder that blew.

As for comparing cubes to strokes, well, all things being equal, in a balanced set up, the longer stroke always makes more torque at a lower RPM. That's why the 327 was used in Rally racing. They wanted to use it in road racing, (Trans Am) but the 5 liter limit caused GM to build the 302. (as I have read) Both 327 and 302 are high revving motors. But they did offer both of them in very large (by today's standards) cars like the Impala that this 327 came from. My mother had a '67 Impala that had a 302.
Not to downgrade here, but in the Honda "Tuner" world, rod/stroke ratio is a huge concern. I won't bore you with specifics, but with a tiny motor, every little thing comes into play.
About the Caddy 500 having loads of torque, (550 in 1970 to be exact), well, we are talking about a 500 cubic inch motor! That's a LOT of displacement! But the 472 makes 525 foot pounds. The difference is just under a quarter of an inch of stroke. At that size, 25 foot pounds is nothing.

As for every 327 and 350 coming from a Vette, mine did too. I was a bigger four door station wagon version of a Vette!!!!

Sorry to sound like a broken record, but to have a more fun car, sell the 327 and use that money to build that 350 block. Being a roller cam, that is good enough reason for me. More torque with the 350, more horsepower in a usable range, so on and so on.... Anyways, the police package gave the Caprice a 350 with TBI and that was a great set up!

And about that 7.5" rear, if it has better gears, use that. You could always go to the scrap yard and get another posi unit for it, if you get tired of peg-leggin'! And like the rest of us, you like to hold on to things, so just hold on to the current rear with posi for later. If you have enough left over from selling the 327, get some gears for it!

06-16-2013 10:28 PM

64nailhead

Quote:

Originally Posted by Valkyrie5.7

I understand that they have no bearing on an engines torque output or high revving capabilities with exception to the most extreme situations.

The Cadillac 500 must have an incredible stroke right? No, actually it's got a square bore/stroke ratio. It's just a big engine that has a drive train designed for a low rpm duty.

Unless you're talking about engines with absolutely monstrous pistons (TD BBC) or very long strokes combined with bores that are strangling past the point of the heads design (the 267 SBC comes to mind) then these rules just don't apply to 90% of performance builds today. You can build a 305, 327 and 350 with nearly identical parts and I can bet they'll make very similar horsepower to one another and the bigger the engine, the faster it'll make peak torque. The smaller the engine will make it's power higher in the rpm range to make the same power as the bigger engine. You read that right, The 305 will have to rev higher to make the same power as the 327, all things being equal.

Short stroke or long stroke or big bore or small bore or freaking rotary or anything... I'll take the bigger engine if I want to make more torque, not the greater stroke. The 327 is going to make more torque at a lower rpm range than the 305 will as long as you use the right components. Valve train and heads. This isn't nitro funny cars... just some small blocks in an old caprice. Bigger is going to be better as long as it's built correctly for it's purpose.

Agreed that the Caddy's big cubes make oodles of torque, but Vinnie is spot on. Bigger rod to stroke ratio makes more torque at higher rpm. Not to be disrespectful, but Isaac Newton wasn't wrong. Check out the tech paper below :

the guy that wrote it goes by 'Panic' and he's beyond pretty sharp. The math doesn't lie.

Bigger rod to stroke ratio equates into greater piston speed at the same rpm as lower rod to stroke ratios. With that being said, timing has to be more precise to maximize the effect of the faster piston speed and vice versa, at lower rpm's a larger rod to stroke ratio has a greater affect on torque.

My favorite example is, of course, a Nailhead (tiny valves), Buick made a 400+ torque motor in the late fifties by maximizing this concept with a 1.875/1.50 valve size.

06-16-2013 06:44 PM

eighty2Bbody

I have found out this engine did come out of a vette but not originally. Its a 275hp 327 out of a Impala with a 4 speed. I put the engine on a stand and removed the oil pan. It actually looks pretty good. All rods and caps have numbers stamped in them and the cross hatch in the cylinders doesn't look factory. There is basically no slug build up any wear so I'm thinking this engine has been rebuilt and there is not very many miles on it. I looked in the spark plug hole and I can see that it has flat top pistons, defiantly not dished. I will not be putting this in my 82, it runs to good to pull out the 305 and put in a mystery condition 327. It's going in my 80 caprice that already has a blown V6, makes a lot more sense to put it in a car that already is in need of a engine. The plan is to run it in the 80 with full length headers (my factory manifolds won't bolt up) and dual exhaust and maybe some 3.73's in the rear. I know a lot of people think this is a waste of time but I like seeing what I can build with spare parts for next to no money invested.

05-10-2013 07:55 PM

ap72

I agree on the weight factor or running a higher stall or better tires, but I'm guessing since this is a caprice you can count on it having passengers and such.

You'd also be surprised what difference the larger bore can have on even 1.94" valves. It'll affect the entire power curve, not just the peak.

05-10-2013 05:52 PM

Valkyrie5.7

[quote=ap72;1674528]

Quote:

Originally Posted by Valkyrie5.7

Well, the 302 should do a little better for one simple, easily understood reason- flow test a set of heads on a 3.75" bore and then on a 4" bore.

Valve shrouding can be a big factor.

To me it's not a make-or-break difference. Maybe 15 or 20hp at the peak between a 305 and 302 with an average set of heads? All this worship of certain engine configurations because there's something magic about them: there's not. Obviously bore shrouding becomes a factor when we're talking big valves, and big numbers. It's the reason the 65-67 Olds 400 is a good performance build and the 68-69 is a turd. I'm not daft, just opinionated.

I may just be the oddball in that I think there's more to making a the average car go fast than eeking every last little hp out of a given motor. And I'm fine with that. On a drag strip, 15hp is an advantage that is broken by a taking out a back seat and avoiding dinner before you head out.

05-10-2013 05:39 PM

eighty2Bbody

Quote:

Originally Posted by 64nailhead

You seem to be a guy that has access to some used parts, i.e., spare transmissions, heads, etc. How about a rear, either complete or gears only. A 3.42 or 3.73 would make your 305 seem like a 400!

Regarding the engine, if you have the time, then put the 327 in your car. But I have to agree with others, that selling this engine and grabbing a 350 will put you ahead in terms of power, torque and money.

Good Luck and happy trails - Jim

Yeah I have an issue with not throwing anything away that I think I mite need in the future, especially sbc stuff. I do have a spare rear end but its the smaller 7.5 inch instead of my current 8.5 and my current rear end has a nice factory posi that I don't want to part with. Not sure what im going to do with the 327, I also have a .040 over 350 one piece rear main block I can build someday but the 327 is a little more rare and that's what I like. It would be a one of a kind car, I have never heard anyone say they had a 327 in a caprice.

05-10-2013 08:48 AM

ap72

[quote=Valkyrie5.7;1674526]

Quote:

Originally Posted by 64nailhead

I appreciate the link and I will check it out to see what it has to say. I'm trying to talk practical applications here: 1.94 valves, keeping it below 6k, you're just not going to see a worthwhile difference between a 302, 305 or 307. 300 cubes is 300 cubes, it's the same engine with some very minor differences in bore and stroke in the grand scheme of things.

Well, the 302 should do a little better for one simple, easily understood reason- flow test a set of heads on a 3.75" bore and then on a 4" bore.

Valve shrouding can be a big factor.

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